The most common oral cavity cancer is squamous cell carcinoma (SCC), of which perineural invasion (PNI) is a significant prognostic factor associated with decreased survival and an increased rate of locoregional recurrence. In the classical theory of PNI, cancer was believed to invade nerves directly through the path of least resistance in the perineural space; however, more recent evidence suggests that PNI requires reciprocal signaling interactions between tumor cells and nerve components, particularly Schwann cells. Specifically, head and neck SCC can express neurotrophins and neurotrophin receptors that may contribute to cancer migration towards nerves, PNI, and neuritogenesis towards cancer. Through reciprocal signaling, recent studies also suggest that Schwann cells may play an important role in promoting PNI by migrating toward cancer cells, intercalating, and dispersing cancer, and facilitating cancer migration toward nerves. The interactions of neurotrophins with their high affinity receptors is a new area of interest in the development of pharmaceutical therapies for many types of cancer. In this comprehensive review, we discuss diagnosis and treatment of oral cavity SCC, how PNI affects locoregional recurrence and survival, and the impact of adjuvant therapies on tumors with PNI. We also describe the molecular and cellular mechanisms associated with PNI, including the expression of neurotrophins and their receptors, and highlight potential targets for therapeutic intervention for PNI in oral SCC.

We reviewed the postoperative functional outcome following surgical resection of paragangliomas in patients with and without preoperative cranial nerve dysfunction. Patients who underwent surgical resections of head and neck paragangliomas were reviewed with functional outcomes defined as feeding tube and/or tracheostomy dependence, need for vocal cord medialization, and incidence of cerebral vascular accidents as primary end points. Secondary end points included pre- and postoperative function of lower cranial nerves and the impact of this dysfunction on long-term functional status. Sixty-one patients were identified: 27 with carotid paraganglioma (CP), 21 with jugular paraganglioma (JP), 8 with tympanic paragangliomas, 4 with vagal paragangliomas (VPs), and 1 with aortopulmonary paraganglioma. Following resection, 8 patients were feeding tube dependent, 14 patients required vocal cord medialization, 2 patients suffered strokes, but no patients required tracheostomy tubes. Twenty percent of patients (4/20) with JP and postoperative cranial neuropathies were feeding tube dependent, and 80% of patients (4/5) with CP and postoperative cranial nerve dysfunction were feeding tube dependent. Cranial nerve deficits were more common in patients with JP relative to those with CP. However, when cranial nerve dysfunction was present, our patients with CP had a higher incidence of temporary feeding tube dependence. Overall, 98% of patients were able to resume oral nutrition.

Although the number of procedures has significantly decreased over the past century, tonsillectomy and adenoidectomy are commonly performed surgeries in the pediatric group, with obstructive sleep apnea being the most common indication. Despite the availability of newer technologies, tonsillectomy is still associated with a relatively high risk of postoperative morbidity. Pain and postoperative bleeding can have a significant impact on the child’s health and quality of life. This article reviews the currently available techniques for tonsillectomy and adenoidectomy, with their characteristics and potential benefits. No gold standard exists at this point, and further prospective clinical trials are needed in this perspective.

Background/Objectives: Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer, with a lifetime risk of 14–20% that is rising every year. Although prognosis for cSCC is generally good, certain high-risk features of cSCC portend increased rates of nodal and distant metastasis, recurrence, and disease-specific mortality. One such high-risk factor is perineural invasion (PNI), which is broadly defined as the invasion of cancer into and around nerves. Compared to other high-risk factors, PNI presence is associated with the highest risk for locoregional and distant metastasis. Still, the mechanisms underlying the pathogenesis of PNI remain poorly understood. Recent studies suggest the migration and invasion of tumors into nerves is a result of complex molecular crosstalk within the tumor-nerve microenvironment, wherein the milieu of signaling molecules simultaneously promote neuronal growth and tumor cell invasion. Methods: Understanding the molecular and cellular mechanisms that promote PNI will lead to future developments of targeted therapies that may improve locoregional control and survival. Results/Conclusions: In our article, we aim to provide a comprehensive review of recent findings about the pathogenesis of PNI, clinical implications of PNI-positive disease in cSCC, available treatment modalities, and potential future therapeutic targets.